There is an organic electroluminescent device that includes a light transmissive first electrode, a light reflective second electrode, and an organic light emitting layer provided between the first electrode and the second electrode. There is an illumination apparatus using the organic electroluminescent device as a light source. There is an illumination system that includes a plurality of organic electroluminescent devices and a controller configured to control to turn-on and turn-off the plurality of organic electroluminescent devices. The organic electroluminescent device is caused to have light permeability in a turn-off state by using a thin-line shaped second electrode, in which a plurality of openings are provided. In such an organic electroluminescent device, it is desired to suppress the infiltration of moisture and the like into an organic light emitting layer.